The invention relates to an electromagnetically actuatable valve, in particular for use in motor vehicles according to the preamble of claim 1.
Electromagnetic valves are made known in the related art, in which the opening and closing of the valve is achieved by means of a moveable solenoid plunger. The disadvantage of this is that, due to the structural arrangement of the components in such valves, an air gap results between coil and center pole, between solenoid plunger and coil, and between solenoid plunger and center pole, which leads to a marked loss of magnetic flux. A further disadvantage of the traditional electromagnetic valves is that, when the valve opens and closes, the solenoid plunger, which is made of iron, strikes the center pole of the magnetic coil and produces a clearly audible noise.
Object of the present invention is to create an electromagnetically actuatable valve of the type described in the preamble of claim 1 that is low-noise or optimized in terms of noise during opening and closing that simultaneously ensures an improved magnetic flux and also saves space.
This object is solved according to the invention using the subject matter of claim 1.
The electromagnetically actuatable valve according to the invention has a magnet part, a moveable armature element, a spring element, and a valve part. The magnet part includes at least one magnetic coil wound on a coil form, a flux concentrating element, and a center pole. The valve part has a closing element that cooperates with the armature element and controls the opening and closing of the valve on a valve seat.
According to the present invention, the armature element of the valve is designed as a clapper-type armature. The use of a clapper-type armature is advantageous, on the one hand, because the entire electromagnetically actuatable valve can then be designed to be smaller in size than when a traditional solenoid plunger is used. This space-saving design of the valve expands its potential uses. On the other hand, the use of a clapper-type armature involves a better efficiency of the magnetic circuit, which is caused, among other things, by the resultant improved possibility of arranging the clapper-type armature relative to the other components of the valve, whereby air gaps that inhibit magnetic flux are largely avoided and only occur between center pole and armature element.
Moreover, the clapper-type armature according to the invention cooperates with the center pole by way of a damping element so that unpleasant noises are prevented when the valve opens and closes. This is particularly important when the electromagnetically actuatable valve is situated in the passenger compartment of a motor vehicle, e.g., in the seats, to vary the seat surface.
The armature element and the valve part are preferably located in a housing. The armature element, the flux concentrating element, the closing element, the spring element as well as the damping element are confined in the housing in pressure-sealed fashion. This can be achieved by pressure-sealed injection of the flux concentrating element. All sensitive components of the valve are therefore protected. The housing can also be designed to be two-piece or multi-piece and be permanently joined by gluing the housing parts together, for example.
In a further preferred embodiment, the electromagnetically actuatable valve has a damping element with a damping stop which absorbs sound, so noise is reduced when the valve opens and closes.
Moreover, the flux concentrating element is preferably designed as a bracket which is situated on the perimeter of the magnetic coil.
In yet another preferred embodiment, the armature element actuates a closing element to open and close the valve, which closing element is designed as an umbrella sealing plug with an umbrella membrane. The umbrella sealing plug is flexible and preferably made out of silicone rubber. As a result, when the clapper-type armature, which is made of iron, strikes the umbrella sealing plug to open the valve, noise is reduced considerably.
The damping element and the closing element can preferably be designed as an integral damping shoe, which also consists entirely of an elastic material such as silicone rubber. This damping shoe can be attached directly to the armature element or it can be injection moulded to it. This embodiment is particularly practical, because the absorption of the sound caused by the striking of the clapper-type armature when the valve opens as well as when it closes can be achieved using the same device, which can be easily and quickly attached to the clapper-type armature by sliding it into place, or it has already been injection moulded to it.